Methods and features for coupling ultrasonic surgical instrument components together

ABSTRACT

A surgical apparatus comprises a transducer assembly and a shaft assembly. The transducer assembly is operable to convert electrical power into ultrasonic vibrations. The shaft assembly comprises an ultrasonic waveguide, a sheath, a shroud, and a torque transfer assembly. The waveguide is configured to couple with the transducer assembly. The waveguide is disposed within the sheath. The sheath extends through the shroud. The torque transfer assembly is contained within the shroud. The torque transfer assembly is configured to transfer a predetermined range of torque from the shroud to the waveguide to thereby couple the waveguide with the transducer assembly. The torque transfer assembly is further configured to prevent transfer of torque from the shroud to the waveguide beyond an upper limit of the predetermined range.

This application is a continuation of U.S. patent application Ser. No.14/087,352, filed Nov. 22, 2013, entitled “Methods and Features forCoupling Ultrasonic Surgical Instrument Components Together,” issued asU.S. Pat. No. 10,226,271 on Mar. 12, 2019.

BACKGROUND

A variety of surgical instruments include an end effector having a bladeelement that vibrates at ultrasonic frequencies to cut and/or sealtissue (e.g., by denaturing proteins in tissue cells). These instrumentsinclude piezoelectric elements that convert electrical power intoultrasonic vibrations, which are communicated along an acousticwaveguide to the blade element. The precision of cutting and coagulationmay be controlled by the surgeon's technique and adjusting the powerlevel, blade edge, tissue traction, and blade pressure.

Examples of ultrasonic surgical instruments include the HARMONIC ACE®Ultrasonic Shears, the HARMONIC WAVE® Ultrasonic Shears, the HARMONICFOCUS® Ultrasonic Shears, and the HARMONIC SYNERGY® Ultrasonic Blades,all by Ethicon Endo-Surgery, Inc. of Cincinnati, Ohio. Further examplesof such devices and related concepts are disclosed in U.S. Pat. No.5,322,055, entitled “Clamp Coagulator/Cutting System for UltrasonicSurgical Instruments,” issued Jun. 21, 1994, the disclosure of which isincorporated by reference herein; U.S. Pat. No. 5,873,873, entitled“Ultrasonic Clamp Coagulator Apparatus Having Improved Clamp Mechanism,”issued Feb. 23, 1999, the disclosure of which is incorporated byreference herein; U.S. Pat. No. 5,980,510, entitled “Ultrasonic ClampCoagulator Apparatus Having Improved Clamp Arm Pivot Mount,” filed Oct.10, 1997, the disclosure of which is incorporated by reference herein;U.S. Pat. No. 6,325,811, entitled “Blades with Functional BalanceAsymmetries for use with Ultrasonic Surgical Instruments,” issued Dec.4, 2001, the disclosure of which is incorporated by reference herein;U.S. Pat. No. 6,773,444, entitled “Blades with Functional BalanceAsymmetries for Use with Ultrasonic Surgical Instruments,” issued Aug.10, 2004, the disclosure of which is incorporated by reference herein;and U.S. Pat. No. 6,783,524, entitled “Robotic Surgical Tool withUltrasound Cauterizing and Cutting Instrument,” issued Aug. 31, 2004,the disclosure of which is incorporated by reference herein.

Still further examples of ultrasonic surgical instruments are disclosedin U.S. Pub. No. 2006/0079874, entitled “Tissue Pad for Use with anUltrasonic Surgical Instrument,” published Apr. 13, 2006, now abandoned,the disclosure of which is incorporated by reference herein; U.S. Pub.No. 2007/0191713, entitled “Ultrasonic Device for Cutting andCoagulating,” published Aug. 16, 2007, now abandoned, the disclosure ofwhich is incorporated by reference herein; U.S. Pub. No. 2007/0282333,entitled “Ultrasonic Waveguide and Blade,” published Dec. 6, 2007, nowabandoned, the disclosure of which is incorporated by reference herein;U.S. Pub. No. 2008/0200940, entitled “Ultrasonic Device for Cutting andCoagulating,” published Aug. 21, 2008, now abandoned, the disclosure ofwhich is incorporated by reference herein; U.S. Pub. No. 2009/0105750,entitled “Ergonomic Surgical Instruments,” published Apr. 23, 2009, nowU.S. Pat. No. 8,623,027, issued Jan. 7, 2014, the disclosure of which isincorporated by reference herein; U.S. Pub. No. 2010/0069940, entitled“Ultrasonic Device for Fingertip Control,” published Mar. 18, 2010, nowU.S. Pat. No. 9,023,071, issued May 5, 2015, the disclosure of which isincorporated by reference herein; and U.S. Pub. No. 2011/0015660,entitled “Rotating Transducer Mount for Ultrasonic SurgicalInstruments,” published Jan. 20, 2011, now U.S. Pat. No. 8,461,744,issued Jun. 11, 2013, the disclosure of which is incorporated byreference herein; and U.S. Pub. No. 2012/0029546, entitled “UltrasonicSurgical Instrument Blades,” published Feb. 2, 2012, now U.S. Pat. No.8,591,536, issued Nov. 26, 2013, the disclosure of which is incorporatedby reference herein.

Some of ultrasonic surgical instruments may include a cordlesstransducer such as that disclosed in U.S. Pub. No. 2012/0112687,entitled “Recharge System for Medical Devices,” published May 10, 2012,now U.S. Pat. No. 9,381,058, issued Jul. 5, 2016, the disclosure ofwhich is incorporated by reference herein; U.S. Pub. No. 2012/0116265,entitled “Surgical Instrument with Charging Devices,” published May 10,2012, now abandoned, the disclosure of which is incorporated byreference herein; and/or U.S. Pat. App. No. 61/410,603, filed Nov. 5,2010, entitled “Energy-Based Surgical Instruments,” the disclosure ofwhich is incorporated by reference herein.

Additionally, some ultrasonic surgical instruments may include anarticulating shaft section. Examples of such ultrasonic surgicalinstruments are disclosed in U.S. patent application Ser. No.13/538,588, filed Jun. 29, 2012, entitled “Surgical Instruments withArticulating Shafts,” now U.S. Pat. No. 9,393,037, issued Jul. 19, 2016,the disclosure of which is incorporated by reference herein; and U.S.patent application Ser. No. 13/657,553, filed Oct. 22, 2012, entitled“Flexible Harmonic Waveguides/Blades for Surgical Instruments,” now U.S.Pat. No. 9,095,367, issued Aug. 4, 2015 the disclosure of which isincorporated by reference herein.

While several surgical instruments and systems have been made and used,it is believed that no one prior to the inventors has made or used theinvention described in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

While the specification concludes with claims which particularly pointout and distinctly claim this technology, it is believed this technologywill be better understood from the following description of certainexamples taken in conjunction with the accompanying drawings, in whichlike reference numerals identify the same elements and in which:

FIG. 1 depicts a perspective view of an exemplary surgical instrument;

FIG. 2A depicts an exploded perspective view of the instrument of FIG.1, showing the instrument in a disassembled state;

FIG. 2B depicts an exploded perspective view of the instrument of FIG.1, showing the instrument in a first partially assembled state;

FIG. 2C depicts an exploded perspective view of the instrument of FIG.1, showing the instrument in a second partially assembled state;

FIG. 2D depicts a perspective view of the instrument of FIG. 1, showingthe instrument in a third partially assembled state;

FIG. 2E depicts a perspective view of the instrument of FIG. 1, showingthe instrument in a fourth partially assembled state;

FIG. 2F depicts an exploded perspective view of the instrument of FIG.1, showing the instrument in a fifth partially assembled state;

FIG. 3A depicts a perspective view of the instrument of FIG. 1, showingthe instrument in a first partially disassembled state;

FIG. 3B depicts an exploded perspective view of the instrument of FIG.1, showing the instrument in a second partially disassembled state;

FIG. 3C depicts an exploded perspective view of the instrument of FIG.1, showing the instrument in a third partially disassembled state;

FIG. 4 depicts a side elevational view of a distal end of the torquewrench of the instrument of FIG. 1;

FIG. 5 depicts a side elevational view of the blade cap of theinstrument of FIG. 1;

FIG. 6 depicts a perspective view of the distal end of the torque wrenchof FIG. 4 positioned to engage the cap of FIG. 5;

FIG. 7 depicts a perspective view of another exemplary alternativesurgical instrument;

FIG. 8A depicts an exploded perspective view of the instrument of FIG.7, showing the instrument in a disassembled state;

FIG. 8B depicts an exploded perspective view of the instrument of FIG.7, showing the instrument in a first partially assembled state;

FIG. 8C depicts an exploded perspective view of the instrument of FIG.7, showing the instrument in a second partially assembled state;

FIG. 8D depicts an exploded perspective view of the instrument of FIG.7, showing the instrument in a third partially assembled state;

FIG. 8E depicts an exploded perspective view of the instrument of FIG.7, showing the instrument in a fourth partially assembled state;

FIG. 8F depicts an exploded perspective view of the instrument of FIG.7, showing the instrument in a fifth partially assembled state;

FIG. 8G depicts a perspective view of the instrument of FIG. 7, showingthe instrument in an assembled state;

FIG. 9 depicts a partial cross-sectional view of the instrument of FIG.7;

FIG. 10 depicts a detailed perspective view of the sheath and theratcheting feature of the instrument of FIG. 7;

FIG. 11A depicts a cross-sectional view of the sheath and the ratchetingfeature of the instrument of FIG. 7, with the sheath in a firstrotational position;

FIG. 11B depicts a cross-sectional view of the sheath and the ratchetingfeature of the instrument of FIG. 7, with the sheath in a secondrotational position;

FIG. 11C depicts a cross-sectional view of the sheath and the ratchetingfeature of the instrument of FIG. 7, with the sheath in a thirdrotational position;

FIG. 12 depicts a perspective view of a connector of the instrument ofFIG. 7;

FIG. 13 depicts a perspective view of yet another exemplary alternativesurgical instrument that uses the sheath, ratcheting feature, andconnector of the instrument of FIG. 7;

FIG. 14A depicts an exploded perspective view of the instrument of FIG.13, showing the instrument in a disassembled state;

FIG. 14B depicts an exploded perspective view of the instrument of FIG.13, showing the instrument in a first partially assembled state;

FIG. 14C depicts an exploded perspective view of the instrument of FIG.13, showing the instrument in a second partially assembled state;

FIG. 14D depicts an exploded perspective view of the instrument of FIG.13, showing the instrument in a third partially assembled state;

FIG. 14E depicts an exploded perspective view of the instrument of FIG.13, showing the instrument in a fourth partially assembled state;

FIG. 14F depicts an exploded perspective view of the instrument of FIG.13, showing the instrument in a fifth partially assembled state;

FIG. 14G depicts a perspective view of the instrument of FIG. 13,showing the instrument in an assembled state;

FIG. 15 depicts a perspective view of the shroud halves of theinstrument of FIG. 13;

FIG. 16 depicts a perspective view of the retaining member of theinstrument of FIG. 13;

FIG. 17A depicts a partial cross-sectional view of the instrument ofFIG. 13, with shroud halves of the shaft assembly in a distal positionand a waveguide of the shaft assembly in a distal position;

FIG. 17B depicts a partial cross-sectional view of the instrument ofFIG. 13, with the shroud halves of the shaft assembly in the distalposition and the waveguide of the shaft assembly in a proximal position;

FIG. 17C depicts a partial cross-sectional view of the instrument ofFIG. 13, with the shroud halves of the shaft assembly in a proximalposition and a waveguide of the shaft assembly in the proximal position;

FIG. 18 depicts a perspective view of yet another exemplary alternativesurgical instrument;

FIG. 19 depicts a perspective view of an exemplary sheath assembly ofthe instrument of FIG. 18;

FIG. 20 depicts a partial perspective view of the instrument of FIG. 18,with a portion of the sheath assembly omitted;

FIG. 21 depicts an exploded perspective view of the sheath assembly ofFIG. 19;

FIG. 22A depicts a cross-sectional view of the ratcheting assembly ofthe instrument of FIG. 18, with a inner radial member in a firstrotational position;

FIG. 22B depicts a cross-sectional view of the ratcheting assembly ofthe instrument of FIG. 18, with the inner radial member in a secondrotational position;

FIG. 22C depicts a cross-sectional view of the ratcheting assembly ofthe instrument of FIG. 18, with the inner radial member in a thirdrotational position;

FIG. 23 depicts a perspective view of yet another exemplary alternativesurgical instrument;

FIG. 24A depicts an exploded perspective view of the instrument of FIG.23, showing the instrument in a disassembled state;

FIG. 24B depicts a perspective view of the instrument of FIG. 23,showing the instrument in a partially assembled state;

FIG. 24C depicts a perspective view of the instrument of FIG. 23,showing the instrument in an assembled state;

FIG. 25 depicts a partial cross-sectional view of the instrument of FIG.23;

FIG. 26 depicts a perspective view of the shroud assembly of theinstrument of FIG. 23;

FIG. 27A depicts a cross-sectional view of the ratcheting assembly ofthe instrument of FIG. 23, with an inner radial member in a firstrotational position;

FIG. 27B depicts a cross-sectional view of the ratcheting assembly ofFIG. 27A, with the inner radial member rotated into a second rotationalposition;

FIG. 27C depicts a cross-sectional view of the ratcheting assembly ofFIG. 27A, with the inner radial member rotated into a third rotationalposition;

FIG. 28 depicts an exploded perspective view of an exemplary shaftassembly of yet another exemplary alternative instrument that uses theratcheting assembly of FIG. 27A;

FIG. 29 depicts a perspective view of the shaft assembly of FIG. 28coupled with the transducer of FIG. 2A;

FIG. 30 depicts a partial cross-sectional view of the instrument of 28;

FIG. 31 depicts a perspective view of the shroud assembly of theinstrument of FIG. 28;

FIG. 32 depicts a perspective of yet another exemplary alternativesurgical instrument;

FIG. 33A depicts an exploded perspective view of the instrument of FIG.32, showing the instrument in a disassembled state;

FIG. 33B depicts an exploded perspective view of the instrument of FIG.32, showing the instrument in a first partially assembled state;

FIG. 33C depicts an exploded perspective view of the instrument of FIG.32, showing the instrument in a second partially assembled state;

FIG. 33D depicts an exploded perspective view of the instrument of FIG.32, showing the instrument in a third partially assembled state;

FIG. 33E depicts a perspective view of the instrument of FIG. 32,showing the instrument in an assembled state;

FIG. 34 depicts a perspective view of a cross-section of a shroud of theinstrument of FIG. 32;

FIG. 35 depicts a perspective view of a sheath of the instrument of FIG.32;

FIG. 36 depicts a partial cross-sectional side view of the instrument ofFIG. 32; and

FIG. 37 depicts a cross-sectional end view of the instrument of FIG. 32,taken along line 37-37 of FIG. 36.

The drawings are not intended to be limiting in any way, and it iscontemplated that various embodiments of the technology may be carriedout in a variety of other ways, including those not necessarily depictedin the drawings. The accompanying drawings incorporated in and forming apart of the specification illustrate several aspects of the presenttechnology, and together with the description serve to explain theprinciples of the technology; it being understood, however, that thistechnology is not limited to the precise arrangements shown.

DETAILED DESCRIPTION

The following description of certain examples of the technology shouldnot be used to limit its scope. Other examples, features, aspects,embodiments, and advantages of the technology will become apparent tothose skilled in the art from the following description, which is by wayof illustration, one of the best modes contemplated for carrying out thetechnology. As will be realized, the technology described herein iscapable of other different and obvious aspects, all without departingfrom the technology. Accordingly, the drawings and descriptions shouldbe regarded as illustrative in nature and not restrictive.

It is further understood that any one or more of the teachings,expressions, embodiments, examples, etc. described herein may becombined with any one or more of the other teachings, expressions,embodiments, examples, etc. that are described herein. Thefollowing-described teachings, expressions, embodiments, examples, etc.should therefore not be viewed in isolation relative to each other.Various suitable ways in which the teachings herein may be combined willbe readily apparent to those of ordinary skill in the art in view of theteachings herein. Such modifications and variations are intended to beincluded within the scope of the claims.

For clarity of disclosure, the terms “proximal” and “distal” are definedherein relative to a human or robotic operator of the surgicalinstrument. The term “proximal” refers the position of an element closerto the human or robotic operator of the surgical instrument and furtheraway from the surgical end effector of the surgical instrument. The term“distal” refers to the position of an element closer to the surgical endeffector of the surgical instrument and further away from the human orrobotic operator of the surgical instrument.

I. Exemplary Ultrasonic Surgical Instrument

FIGS. 1-6 illustrate an exemplary ultrasonic surgical instrument (10).At least part of instrument (10) may be constructed and operable inaccordance with at least some of the teachings of U.S. Pat. Nos.5,322,055; 5,873,873; 5,980,510; 6,325,811; 6,773,444; 6,783,524; U.S.Pub. No. 2006/0079874, now abandoned; U.S. Pub. No. 2007/0191713, nowabandoned; U.S. Pub. No. 2007/0282333, now abandoned; U.S. Pub. No.2008/0200940, now abandoned; U.S. Pub. No. 2009/0105750, now U.S. Pat.No. 8,623,027; U.S. Pub. No. 2010/0069940 now U.S. Pat. No. 9,023,071;U.S. Pub. No. 2011/0015660, now U.S. Pat. No. 8,461,744; U.S. Pub. No.2012/0112687, now U.S. Pat. No. 9,381,058; U.S. Pub. No. 2012/0116265now abandoned; U.S. patent application Ser. No. 13/538,588, now U.S.Pat. No. 9,393,037; U.S. patent application Ser. No. 13/657,553, nowU.S. Pat. No. 9,095,367; U.S. Pat. App. No. 61/410,603; and/or U.S.patent application Ser. No. 14/028,717, now U.S. Pat. No. 10,172,636,issued Jan. 8, 2019. The disclosures of each of the foregoing patents,publications, and applications are incorporated by reference herein. Asdescribed therein and as will be described in greater detail below,instrument (10) is operable to cut tissue and seal or weld tissue (e.g.,a blood vessel, etc.) substantially simultaneously. It should also beunderstood that instrument (10) may have various structural andfunctional similarities with the HARMONIC ACE® Ultrasonic Shears, theHARMONIC WAVE® Ultrasonic Shears, the HARMONIC FOCUS® Ultrasonic Shears,and/or the HARMONIC SYNERGY® Ultrasonic Blades. Furthermore, instrument(10) may have various structural and functional similarities with thedevices taught in any of the other references that are cited andincorporated by reference herein.

To the extent that there is some degree of overlap between the teachingsof the references cited herein, the HARMONIC ACE® Ultrasonic Shears, theHARMONIC WAVE® Ultrasonic Shears, the HARMONIC FOCUS® Ultrasonic Shears,and/or the HARMONIC SYNERGY® Ultrasonic Blades, and the followingteachings relating to instrument (10), there is no intent for any of thedescription herein to be presumed as admitted prior art. Severalteachings herein will in fact go beyond the scope of the teachings ofthe references cited herein and the HARMONIC ACE® Ultrasonic Shears, theHARMONIC WAVE® Ultrasonic Shears, the HARMONIC FOCUS® Ultrasonic Shears,and the HARMONIC SYNERGY® Ultrasonic Blades.

Instrument (10) of the present example comprises a transducer assembly(100), an acoustic waveguide (20), and a shroud (30). A proximal end ofwaveguide (20) includes a threaded bore (22). A distal end of waveguide(20) includes an ultrasonic blade (24). Ultrasonic blade (24) of thepresent example has a scoop-like shape. It should be understood thatultrasonic blade (24) may comprise a curved blade (e.g. EthiconEndo-Surgery, Inc. Product Code SNGCB), a hook blade (e.g. EthiconEndo-Surgery, Inc. Product Code SNGHK), a combination hook blade (e.g.Ethicon Endo-Surgery, Inc. Product Code SNGHK2). As yet another merelyillustrative example, blade (24) may be constructed in accordance withat least some of the teachings of U.S. Provisional Patent App. No.61/734,636, entitled “Ultrasonic Surgical Blade,” filed Dec. 7, 2012,the disclosure of which is incorporated by reference herein; and/or U.S.Pat. No. 8,057,498, entitled “Ultrasonic Surgical Instrument Blades,”issued Nov. 15, 2011, the disclosure of which is incorporated byreference herein. Other suitable configurations that may be used forblade (24) will be apparent to those of ordinary skill in the art inview of the teachings herein.

As will be discussed in more detail below, waveguide (20) is configuredto transfer ultrasonic vibrations from transducer assembly (100) toultrasonic blade (24) to thereby sever and/or seal tissue. A proximalend of shroud (30) threadably couples with a distal end of transducerassembly (100). Shroud (30) defines an interior bore (32) that passescompletely through shroud (30) from the proximal end to a distal endthus defining a proximal opening and a distal opening. Waveguide (20) isdisposed within interior bore (32) of shroud (30) such that waveguide(20) may be threadably coupled with transducer assembly (100) via theproximal opening of shroud (30). A distal portion of waveguide (20),including ultrasonic blade (24), projects distally from a distal end ofshroud (30) via the distal opening of shroud (30).

Transducer assembly (100) of the present example is coupled to agenerator (16) via a cable (14), though it should be understood thattransducer assembly (100) may instead be a cordless transducer. As bestseen in FIG. 2A, transducer assembly (100) comprises a housing (110), afirst conductive ring (102), a second conductive ring (104), and a horn(120). As will be discussed in more detail below, horn (120) comprises athreaded stud (122) extending distally therefrom such that horn (120) isconfigured to couple with a threaded bore (22) formed in a proximal endof waveguide (20). In some versions, first conductive ring (102)comprises a ring member that is disposed between housing (110) and horn(120). First conductive ring (102) is formed within a cavity (108) oftransducer assembly (100) such that first conductive ring (102) iselectrically isolated from second conductive ring (104) and otherconductive components of transducer assembly (100). First conductivering (102) is located on a non-conductive platform extending distallyfrom housing (110). First conductive ring (102) is electrically coupledto cable (14), shown in FIG. 1, by one or more electrical wires orconductive etchings (not shown) within housing (110).

Second conductive ring (104) of transducer assembly (100) similarlycomprises a ring member that is disposed between housing (110) and horn(120). In particular, second conductive ring (104) is disposed betweenfirst conductive ring (102) and horn (120). As is shown in FIG. 2A,first and second conductive rings (102, 104) are concentric members thatare longitudinally offset from each other, with conductive ring (102)also being positioned at a greater radial distance from the central axisshared by conductive rings (102, 104). Second conductive ring (104) islikewise electrically isolated from first conductive ring (102) andother conductive components of transducer assembly (100). Similar tofirst conductive ring (102), second conductive ring (104) extendsdistally from a non-conductive platform. A washer-shaped spacer (112) isinterposed between second conductive ring (102) and horn (120) in thisexample. It should be understood that one or more additionalwasher-shaped spacers (112) may be disposed between first and secondconductive rings (102, 104) or between the rings (102, 104) and othercomponents of transducer assembly (100). Second conductive ring (104) isalso electrically coupled to cable (14), shown in FIG. 1, by one or moreelectrical wires or conductive etchings (not shown) within housing(110). By way of example only, transducer assembly (100) may beconstructed and operable in accordance with a Model No. HP054 transducerassembly by Ethicon Endo-Surgery, Inc. of Cincinnati, Ohio.

As previously discussed, the distal end of transducer assembly (10)threadably couples with threaded bore (22) formed in the proximal end ofwaveguide (20) via threaded stud (122) of horn (120). The distal end oftransducer assembly (100) also interfaces with one or more electricalconnections (not shown) via first and second conductive rings (102, 104)to electrically couple transducer assembly (100) to buttons (not shown)of instrument (10) to provide a user with finger-activated controls foractivating transducer assembly (100) while using surgical instrument(10). An operator may activate the buttons to selectively activatetransducer assembly (100) to activate ultrasonic blade (24). Instrument(10) may comprise a pair of buttons—one for activating ultrasonic blade(24) at a low power and another for activating ultrasonic blade (24) ata high power. Of course, any other suitable number of buttons and/orotherwise selectable power levels may be provided. The buttons may bepositioned such that an operator may readily fully operate instrument(10) with a single hand. Furthermore, hand activated buttons may besupplemented by or substituted with a foot pedal assembly that may beused to selectively activate transducer assembly (100). Still othersuitable configurations for transducer assembly (100), and features thatmay be used to selectively activate transducer assembly (100), will beapparent to one of ordinary skill in the art in view of the teachingsherein. For instance, first and second conductive rings (102, 104) maybe omitted from the distal end of transducer assembly (100) and theelectrical coupling of transducer assembly (100) to the buttons may beaccomplished by alternative features, such as conductors at the proximalend of transducer assembly (100), conductors located along the side ofhousing (110) of transducer assembly (100), directly from cable (14),and/or any other structures and configurations as will be apparent toone of ordinary skill in the art in view of the teachings herein.

Transducer assembly (100) includes a piezoelectric stack (not shown)within housing (110). When transducer assembly (100) of the presentexample is activated, an electric field is created in the piezoelectricstack, causing the piezoelectric stack and horn (120) to oscillatewithin and relative to housing (110). A mounting flange (not shown) isused to couple horn (120) to housing (110), to thereby structurallysupport the piezoelectric stack in housing (110). The mounting flangemay be located at a node associated with resonant ultrasonic vibrationscommunicated from the piezoelectric stack to horn (120). Transducerassembly (100) is operable to create mechanical energy, or vibrations,at an ultrasonic frequency (such as 55.5 kHz). If transducer assembly(100) is coupled to waveguide (20) via horn (120), then these mechanicaloscillations are transmitted through waveguide (20) to ultrasonic blade(24). In the present example, ultrasonic blade (24), being coupled towaveguide (20), oscillates at the ultrasonic frequency. Thus, whenultrasonic blade (24) contacts tissue, the ultrasonic oscillation ofultrasonic blade (24) may sever and/or seal the tissue. An electricalcurrent may also be provided through ultrasonic blade (24) to cauterizethe tissue. For instance, monopolar or bipolar RF energy may be providedthrough ultrasonic blade (24). While some configurations for transducerassembly (100) have been described, still other suitable configurationsfor transducer assembly (100) will be apparent to one of ordinary skillin the art in view of the teachings herein.

As previously discussed, transducer assembly (100) is coupled with agenerator (16) via a cable (14). Transducer assembly (100) receiveselectrical power from generator (16) and converts that power intoultrasonic vibrations through piezoelectric principles. Generator (16)may include a power source and control module that is configured toprovide a power profile to transducer assembly (100) that isparticularly suited for the generation of ultrasonic vibrations throughtransducer assembly (100). By way of example only, generator (16) maycomprise a GEN 300 sold by Ethicon Endo-Surgery, Inc. of Cincinnati,Ohio. In addition or in the alternative, generator (16) may beconstructed in accordance with at least some of the teachings of U.S.Pub. No. 2011/0087212, entitled “Surgical Generator for Ultrasonic andElectrosurgical Devices,” published Apr. 14, 2011, now U.S. Pat. No.8,986,302, issued Mar. 24, 2015, the disclosure of which is incorporatedby reference herein. It should also be understood that at least some ofthe functionality of generator (16) may be integrated into instrument(100), and that instrument (10) may even include a battery or otheron-board power source such that cable (14) is omitted. Still othersuitable forms that generator (16) may take, as well as various featuresand operabilities that generator (16) may provide, will be apparent tothose of ordinary skill in the art in view of the teachings herein.

Ultrasonic vibrations that are generated by transducer assembly (100)are communicated along an acoustic waveguide (20), which extends throughshroud (30) to reach ultrasonic blade (24). As noted above, whenultrasonic blade (24) is in an activated state (i.e., vibratingultrasonically), ultrasonic blade (24) is operable to effectively cutthrough and seal tissue. It should be understood that waveguide (20) maybe configured to amplify mechanical vibrations transmitted throughwaveguide (20). Furthermore, waveguide (20) may include featuresoperable to control the gain of the longitudinal vibrations alongwaveguide (20) and/or features to tune waveguide (20) to the resonantfrequency of the system.

In the present example, the distal end of ultrasonic blade (24) islocated at a position corresponding to an anti-node associated withresonant ultrasonic vibrations communicated through waveguide (20), inorder to tune the acoustic assembly to a preferred resonant frequencyf_(o) when the acoustic assembly is not loaded by tissue. Whentransducer assembly (100) is energized, the distal end of ultrasonicblade (24) is configured to move longitudinally in the range of, forexample, approximately 10 to 500 microns peak-to-peak, and in someinstances in the range of about 20 to about 200 microns at apredetermined vibratory frequency f_(o) of, for example, 55.5 kHz. Whentransducer assembly (100) of the present example is activated, thesemechanical oscillations are transmitted through waveguide (20) to reachultrasonic blade (24), thereby providing oscillation of ultrasonic blade(24) at the resonant ultrasonic frequency. Thus, when tissue iscontacted by ultrasonic blade (24), the ultrasonic oscillation ofultrasonic blade (24) may simultaneously sever the tissue and denaturethe proteins in adjacent tissue cells, thereby providing a coagulativeeffect with relatively little thermal spread. In some versions, anelectrical current (e.g., in the RF range) may also be provided throughultrasonic blade (24) to further seal the tissue. While someconfigurations for an acoustic transmission assembly and transducerassembly (100) have been described, still other suitable configurationsfor an acoustic transmission assembly and transducer assembly (100) willbe apparent to one or ordinary skill in the art in view of the teachingsherein.

The foregoing components and operabilities of instrument (10) are merelyillustrative. Instrument (10) may be configured in numerous other waysas will be apparent to those of ordinary skill in the art in view of theteachings herein. By way of example only, at least part of instrument(10) may be constructed and/or operable in accordance with at least someof the teachings of any of the following, the disclosures of which areall incorporated by reference herein: U.S. Pat. Nos. 5,322,055;5,873,873; 5,980,510; 6,325,811; 6,783,524; U.S. Pub. No. 2006/0079874,now abandoned; U.S. Pub. No. 2007/0191713 now abandoned; U.S. Pub. No.2007/0282333, now abandoned; U.S. Pub. No. 2008/0200940, now abandoned;U.S. Pub. No. 2010/0069940, now U.S. Pat. No. 9,023,071; U.S. Pub. No.2011/0015660, now U.S. Pat. No. 8,461,744; U.S. Pub. No. 2012/0112687,now U.S. Pat. No. 9,381,058; U.S. Pub. No. 2012/0116265, now abandoned;U.S. patent application Ser. No. 13/538,588, now U.S. Pat. No.9,393,037; and/or U.S. patent application Ser. No. 13/657,553, now U.S.Pat. No. 9,095,367. Additional merely illustrative variations forinstrument (10) will be described in greater detail below. It should beunderstood that the below described variations may be readily applied toinstrument (10) described above and any of the instruments referred toin any of the references that are cited herein, among others.

FIGS. 2A-2F show exemplary assembly steps of instrument (10). FIG. 2Ashows instrument (10) in a disassembled state, with transducer assembly(100), shroud (30), waveguide (20), and a torque wrench (50) separatedfrom each other. Torque wrench (50) may be configured and operable inaccordance with at least some of the teachings of U.S. Pub. No.2007/0191713, now abandoned, entitled “Ultrasonic Device for Cutting andCoagulating,” published Aug. 16, 2007, the disclosure of which isincorporated by reference herein. A cap (40) is positioned aboutultrasonic blade (24) such that cap (40) rotates with waveguide (20) aswill be described in greater detail below. During a first stage ofassembly, a proximal end of shroud (30) is threadably coupled to asleeve portion (106) of transducer assembly (100) as shown in FIG. 2B.In other words, shroud (30) is maneuvered proximally into engagementwith sleeve portion (106); and is then rotated relative to transducerassembly (100) to secure shroud (30) to transducer assembly (100)through a threaded coupling. In some variations, shroud (30) is securedto sleeve portion (106) through complementary bayonet mount featuresand/or other kinds of coupling features.

Once shroud (30) has been coupled with transducer assembly (100),waveguide (20) is inserted through the distal opening of shroud (30) andinto interior bore (32) as shown in FIG. 2C, such that a user maythreadably couple waveguide (20) to threaded stud (122) of transducerassembly (100) via threaded bore (22) formed within the proximal end ofwaveguide (20). The distal portion of waveguide (20), includingultrasonic blade (24) and cap (40), extends projects from shroud (30)via the distal opening of shroud (30) such that cap (40) is completelyexposed. It should be understood that at this point, the user will onlyhave hand tightened waveguide (20) to transducer assembly (100).

Once waveguide (20) has been partially secured to transducer assembly(100) as shown in FIG. 2C, the proximal end of torque wrench (50) isthen positioned about cap (40) as shown in FIG. 2D. In the presentexample, torque wrench (50) couples with cap (40) through a snap fittingsuch that rotation of torque wrench (50) causes rotation of cap (40) andwaveguide (20). As best seen in FIGS. 4-6, the proximal end of torquewrench (50) includes a pocket (52) defined by a rigid base member (54)and a resilient latching member (56). Pocket (52) is configured toreceive cap (40). An interior surface of base member (54) complements abottom exterior surface of cap (40). Latching member (56) includes aninwardly extending tab (58). A proximal surface of tab (58) is angledsuch that as cap (40) is driven into pocket (52), contact between cap(40) and tab (58) drives latching member (56) outwardly to allow cap(40) to pass into pocket (52). Once cap (40) reaches a predetermineddepth within pocket (52), latching member (56) snaps back into placethereby coupling about an edge (42) of cap (40), such torque wrench (50)is coupled with cap (40) through engagement between tab (58) and ashoulder (44) of cap (40). Once torque wrench (50) is coupled with cap(40), torque wrench (50) may be rotated relative to transducer assembly(100) to thereby further tighten waveguide (20) to transducer assembly(100) as shown in FIG. 2E. In some variations, torque wrench (50) isalready coupled with cap (40) at the stages shown in FIGS. 2A-2C, suchthat torque wrench (50) may be used as a grip to facilitate maneuveringof waveguide (20) into initial engagement with threaded stud (122).

As the user rotates waveguide (20) relative to transducer assembly (100)via torque wrench (50) as shown in FIG. 2E, torque wrench (50) isconfigured to signal the user when waveguide (20) has been coupled withtransducer assembly (100) at an appropriate torque value. For instance,torque wrench (50) may be configured to audibly and/or tangibly signalto a user that waveguide (20) has been appropriately connected withtransducer assembly (100), such as by emitting audible and/or tangibleclicks. In the present example, torque wrench (50) emits two audibleclicks once the appropriate torque has been reached between waveguide(20) and transducer assembly (100). In addition to providing audibleand/or tactile feedback to the user to indicate suitable coupling ofwaveguide (20) with transducer assembly (100), torque wrench (50) mayalso effectively restrict the amount of torque that may be appliedthrough the coupling of waveguide (20) with transducer assembly. Forinstance, once the appropriate amount of torque has been reached, torquewrench (50) may provide rotational slipping relative to waveguide (20),such that further rotation of torque wrench (50) relative to transducerassembly (100) will not provide further rotation of waveguide (20)relative to transducer assembly (100). Various features that may be usedto provide audible/tactile feedback and rotational slipping will bedescribed in greater detail below; while other examples of such featureswill be apparent to those of ordinary skill in the art in view of theteachings herein.

As shown in FIG. 2F, torque wrench (50) may be pulled distally away fromwaveguide (20) after waveguide (20) has been coupled with transducerassembly (100) at the appropriate torque. As also shown in FIG. 2F, cap(40) remains coupled with torque wrench (50) as torque wrench is pulleddistally away from waveguide (20). By way of example only, a grippingtab (46) (see FIG. 6) of cap (40) may resiliently bear against blade(24) and thereby provide a friction fit that secures cap (40) to blade(24), such that the user need only overcome the friction betweengripping tab (46) and blade (24) in order to remove cap (40) from blade(24). Once torque wrench (50) and cap (40) are pulled away fromwaveguide (20) and blade (24), instrument (10) may be operated like anyother ultrasonic scalpel. Various suitable ways in which instrument (10)may be used once blade (24) has been exposed will be apparent to thoseof ordinary skill in the art in view of the teachings herein.

FIGS. 3A-3C show exemplary disassembly steps of instrument (10). In thepresent example, the user has set aside the combination of torque wrench(50) and cap (40) during use of instrument (10) in a surgical procedure,and now returns to using the combination of torque wrench (50) and cap(40) to disassemble instrument (10). In particular, the user graspstorque wrench (50) and maneuvers torque wrench (50) to slide cap (40)proximally back onto blade (24) as shown in FIG. 3A. As also shown inFIG. 3A, the user rotates torque wrench (50) and cap (40) once cap (40)is secured to blade (24), thereby rotating waveguide (20) relative totransducer assembly (100) to disengage threaded stud (122) of transducerassembly (100) form threaded bore (22) of waveguide (20). As shown inFIG. 3B, once waveguide (20) is completely loosened from transducerassembly (100), torque wrench (50), cap (40), and waveguide (20)together may be removed from shroud (30) via the distal opening ofshroud (30). As shown in FIG. 3C, shroud (30) may then be decoupled fromsleeve portion (106) of transducer assembly (100). At this point, torquewrench (50), cap (40), waveguide (20), and shroud (30) may be disposedof; while transducer assembly (100) may be reconditioned any re-used.Alternatively, the user may wish to handle these components in someother fashion.

II. Exemplary Ultrasonic Surgical Instruments with Integral TorqueAssembly

In some versions of instrument (10), it may be desirable to incorporatethe torque limiting features of torque wrench (50) within instrument(10), such that a separate component like torque wrench (50) is notneeded. In particular, it may be desirable to provide instrument (10)with integral features that indicate to the user when an appropriateamount of torque has been applied to secure waveguide (20) withtransducer assembly (100). In addition or in the alternative, it may bedesirable to provide instrument (10) with integral features that limitthe amount of torque that may be applied to secure waveguide (20) withtransducer assembly (100). Several illustrative examples of variationsof instrument (10) that include integral torque assemblies will bedescribed in greater detail below. Further examples will be apparent tothose of ordinary skill in the art in view of the teachings herein.

A. Exemplary Integral Torque Assembly with Dual Shroud and RetainingRings

FIGS. 7-12 show an exemplary instrument (200) having an integral torqueassembly (250). Instrument (200) of the present example is configured tooperate substantially similar to instrument (10) discussed above exceptfor the differences discussed below. In particular, instrument (200) isthus operable to transect and/or seal tissue at a surgical site.Instrument (200) of the present example comprises transducer assembly(100) and a shaft assembly (210). Shaft assembly (210) comprises awaveguide (220), a sheath (230), a pair of shroud halves (240, 242), apair of retaining rings (244, 246), a torque member (250), and aconnector (260). Shaft assembly (210) also includes a user input feature(211) that is operable to selectively activate transducer assembly(100), to thereby selectively activate ultrasonic blade (224) ofwaveguide (220). User input feature (211) may include one or moreswitches and/or various other components. By way of example only, userinput feature (211) may be constructed and operable in accordance withat least some of the teachings of U.S. Pub. No. 2010/0069940, entitled“Ultrasonic Device for Fingertip Control,” published Mar. 18, 2010, nowU.S. Pat. No. 9,023,071, the disclosure of which is incorporated byreference herein. As another merely illustrative example, user inputfeature (211) may be constructed and operable in accordance with atleast some of the teachings of U.S. Pub. No. 2012/0203213, entitled“Activation Feature for Surgical Instrument with Pencil Grip,” publishedAug. 9, 2012, now U.S. Pat. No. 9,107,688, issued Aug. 18, 2015, thedisclosure of which is incorporated by reference herein. Still othersuitable ways in which user input feature may be constructed andoperable will be apparent to those of ordinary skill in the art in viewof the teachings herein.

As shown in FIG. 10, sheath (230) defines a longitudinal interior bore(232) that passes completely through sheath (230) from a proximal end toa distal end, such that bore (232) defines a proximal opening and adistal opening. Bore (232) is configured to receive waveguide (220). Aproximal end of sheath (230) includes an annular flange (234) and aplurality of longitudinal projections (236) extending radially outwardlyfrom an exterior surface of sheath (230). Torque member (250) defines alongitudinal interior bore (252) that passes completely through torquemember (250) from a proximal end to a distal end, such that bore (252)defines a proximal opening and a distal opening. Interior bore (252) oftorque member (250) is configured to receive sheath (230) such that aproximal surface of torque member (250) rests against a distal surfaceof flange (234). Sheath (230) is rotatably disposed within interior bore(252). Torque member (250) includes a pair of resilient members (254)formed on opposite sides of torque member (250). Each resilient member(254) includes an inwardly extending tab (256). As will be discussed inmore detail below, tabs (256) engage projections (236) to transferrotation of torque member (250) to sheath (230). As will also bediscussed in more detail below, a surface (256A) of each tab (256) and asurface (236A) of each longitudinal projection (236) are angled suchthat as torque member (250) is rotated clockwise about sheath (230),contact between longitudinal projections (236) of sheath and tabs (256)drive resilient members (254) outwardly to allow torque member (250) tobe rotated without rotating sheath (230) once waveguide (220) is securedto transducer assembly (100) with an appropriate amount of torque.

FIGS. 8A-8G show exemplary steps for assembling instrument (200). FIG.8A shows instrument (200) in a disassembled state, including shaftassembly (210) in a disassembled state. In an initial assembly step,waveguide (220) is inserted into interior bore (232) of sheath (230)such that ultrasonic blade (224) of waveguide (220) extends from thedistal end of sheath (230) as shown in FIG. 8B. A pin (226) is passedthrough aligned openings (238, 228) in sheath (230) and waveguide (220)to thereby couple sheath (230) and waveguide (220), such that rotationof sheath (230) causes concurrent rotation of waveguide (220). It shouldtherefore be understood that sheath (230) and waveguide (220) rotatetogether unitarily when shaft assembly (210) is fully assembled. Opening(228) is located at a position along the length of waveguide (220)corresponding to a node associated with resonant ultrasonic vibrationscommunicated through waveguide (220), such that the ultrasonicvibrations are not communicated to pin (226).

With sheath (230) and waveguide (220) coupled together, connector (260)is then coupled to a proximal surface of flange (234) of sheath (230) asshown in FIG. 8C. Connector (260) is configured to insertingly fit incavity (108) of transducer assembly (100) and thereby guide shaftassembly (210) into aligned engagement with transducer assembly (100).As shown in FIG. 12, connector (260) comprises an annular distal flange(261), a first electrical contact feature (262), and a second electricalcontact feature (265). First electrical contact feature (262) includesoutwardly extending protrusions (263) that are configured to engagefirst conductive ring (102) when connector (260) is inserted in cavity(108) of transducer assembly (100). First electrical contact feature(262) also includes a distally projecting feature (264) that isconfigured to couple with a wire, trace, and/or other conductive featurethat is in communication with user input feature (211) of shaft assembly(210). Similarly, second electrical contact feature (265) includesoutwardly extending protrusions (266) that are configured to engagesecond conductive ring (104) when connector (260) is inserted in cavity(108) of transducer assembly (100). Second electrical contact feature(265) also includes a distally projecting feature (267) that isconfigured to couple with a wire, trace, and/or other conductive featurethat is in communication with user input feature (211) of shaft assembly(210). Electrical contact features (262, 265) thus provide electricalcoupling between user input feature (211) and transducer assembly (100).

As shown in FIG. 8D, torque member (250) is then positioned about sheath(230) such that the proximal surface of torque member (250) restsagainst the distal surface of flange (234). As noted above, sheath (230)fits into bore (252) of torque member (250), such that torque member(250) may simply be slid onto sheath (230). It should be understood thatthe steps shown in FIGS. 8C and 8D may be reversed, performedsimultaneously, or otherwise be combined with other assembly stepsdescribed herein.

Once connector (260) and torque member (250) have been suitablypositioned in relation to sheath (230), and sheath (230) and waveguide(220) have been coupled together, shroud halves (240, 242) are thenmaneuvered toward sheath (230) such that the proximal portion of sheath(230) is captured between shroud halves (240, 242) as shown in FIG. 8E.Referring back to FIG. 10, an exterior surface of torque member (250)presents a pair of longitudinal channels (258) in the present example.The interior regions of shroud halves (240, 242) each include arespective key feature (not shown) that is configured to fit withinchannels (258) of torque member (250) when shroud halves (240, 242) arepositioned about torque member (250). Thus, as shroud halves (240, 242)are rotated, torque member (250) is concurrently rotated. It shouldtherefore be understood that shroud halves (240, 242) and torque member(250) rotate together unitarily when shaft assembly (210) is fullyassembled. The distal end of each shroud half (240, 242) includes arespective recess (241, 245). Recesses (241, 245) align with each otherto form a complete annular recess when shroud halves (240, 242) arejoined together as shown in FIG. 8E. Similarly, the proximal end of eachshroud half (240, 242) includes a respective recess (243, 247). Recesses(243, 247) also align with each other to form a complete annular recesswhen shroud halves (240, 242) are joined together as shown in FIG. 8E.

Once shroud halves (240, 242) have been joined together as shown in FIG.8E, a distal retaining ring (244) is slid proximally over alignedrecesses (241, 245), as shown in FIG. 8F. Similarly, a proximalretaining ring (246) is slid distally over aligned recesses (243, 247),as also shown in FIG. 8F. Retaining rings (244, 246) are configured tohold shroud halves (240, 242) together. At this stage, shaft assembly(210) is completely assembled. Retaining rings (244, 246) may engageshroud halves (240, 242) with an interference fit, such that retainingrings (244, 246) remain coupled with shroud halves (240, 242) due tofriction. It should be understood that shaft assembly (210) may beprovided to an end user in the configuration shown in FIG. 8F, such thatthe end user need not perform any of the assembly steps shown in FIGS.8A-8F.

Once shaft assembly (210) has been fully assembled, shaft assembly (210)may be readily coupled with transducer assembly (100) as shown in FIGS.8G and 9. In particular, the user may first maneuver shaft assembly(210) proximally toward transducer assembly (100). During this stage,connector (260) may assist in guiding shaft assembly (210) into axialalignment with transducer assembly (100) as noted above. The user maythen grasp shroud halves (240, 242) and rotate shaft assembly (210)relative to transducer assembly (100) to mechanically and acousticallycouple waveguide (220) with horn (120) via threaded stud (122) and athreaded bore (222) formed in a proximal end of waveguide (220).

FIGS. 11A-11C show the interaction of torque member (250) and sheath(230) as waveguide (220) is connected with transducer assembly (100)through rotation of shaft assembly (210) relative to transducer assembly(100). It should be understood that the stages shown in FIGS. 11A-11Ccorrespond with the stage shown in FIG. 8G. It should also be understoodthat, during the stages shown in FIGS. 11A-11C, the user may be graspingtransducer assembly (100) with one hand and grasping shroud halves (240,242) with the other hand, thereby rotating shroud halves (240, 242)relative to transducer assembly (100). As shroud halves (240, 242) arerotated clockwise relative to transducer assembly (100), torque member(250) rotates as well because of the engagement between the key featuresof shroud halves (240, 242) and longitudinal channels (258) of torquemember (250). During the initial stage of this rotation, tabs (256)rotate into engagement with longitudinal projections (236) as shown inFIG. 11A. With tabs (256) engaging longitudinal projections (236), theuser continues to rotate shroud halves (240, 242) clockwise relative totransducer assembly (100) through a first range of motion. During thisfirst range of motion, tabs (256) continue to engage longitudinalprojections (236) such that torque member (250) rotates sheath (230) andwaveguide (220) relative to transducer assembly (100). Waveguide (220)is thereby coupled with threaded stud (122).

As the user completes the first range of motion, waveguide (220) issecured to threaded stud (122) with a certain predetermined amount oftorque. Once the assembly of waveguide (220) and threaded stud (122)reaches the predetermined amount of torque, and the user continues torotate shroud halves (240, 242) clockwise relative to transducerassembly (100) past the first range of motion, resilient members (254)deflect outwardly as shown in FIG. 11B. In particular, angular surfaces(236A) of longitudinal projections (236) and angular surface (256A) oftabs (256) drive resilient members (254) outwardly through a cam action,such that torque member (250) no longer rotates sheath (230). As theuser continues to rotate shroud halves (240, 242), torque member (250)continues to rotate such that tabs (256) eventually clear longitudinalprojections (236) and snap inwardly as shown in FIG. 11C. This inwardsnapping/ratcheting may provide audible and/or tactile feedback toindicate to the user that an appropriate amount of torque has beenachieved in the coupling of waveguide (220) with threaded stud (122). Itshould be understood that from this point on, any further clockwiserotation of shroud halves (240, 242) and torque member (250) no longercauses rotation of sheath (230) and waveguide (220) relative totransducer assembly (100). It should also be understood that therigidity of resilient members (254) may be changed to thereby change themaximum amount of torque that may be applied to waveguide (220).

A surface (256B) of each tab (256) and a surface (236B) of eachlongitudinal projection (236) is substantially flat such that as torquemember (250) is rotated counterclockwise relative to transducer assembly(100), contact between longitudinal projections (236) of sheath and tabs(256) will not drive resilient members (254) outwardly. It shouldtherefore be understood that rotation of shroud halves (240, 242) andtorque member (250) relative to transducer assembly (100) in acounterclockwise motion will not cause slipping or ratcheting of torquemember (250). Thus, when the user wishes to disassemble shaft assembly(210) from transducer assembly (100) at the end of a surgical procedure,the user may simply grasp shroud halves (240, 242) with one hand androtate shroud halves (240, 242) counterclockwise relative to transducerassembly (100) while gripping transducer assembly (100) with the otherhand, until waveguide (220) is decoupled from threaded stud (122) oftransducer assembly (100). The user may then simply pull shaft assembly(210) away from transducer assembly (100). At this stage, shaft assembly(210) may be disposed of; while transducer assembly (100) may bereconditioned any re-used. Alternatively, the user may wish to handlethese components in some other fashion.

It should be understood that the integral torque assembly features ofshaft assembly (210) eliminate the need for a separate torque wrench(e.g., such as torque wrench (50), etc.) to secure waveguide (220) withhorn (120). It should also be understood that, during use of assembledinstrument (200), the distal portion of sheath (230) proximal toultrasonic blade (224) may be grasped by a user during operation tograsp instrument (200) in a pencil-like manner. Holding instrument (200)with a pencil grip may enable the user to provide very fine and precisemovement with blade (224), such as in a facial plastic surgery procedureor some other fine and precise surgical procedure.

B. Exemplary Integral Torque Assembly with Dual Shroud and ResilientFeatures

FIGS. 13-17C show another exemplary instrument (300) that incorporatestorque assembly (250), sheath (230), and connector (260) of instrument(200) discussed above. Instrument (300) of the present example isconfigured to operate substantially similar to instruments (10, 200)discussed above except for the differences discussed below. Instrument(300) is thus operable to transect and/or seal tissue at a surgicalsite. Furthermore, torque member (250) is configured to operatesubstantially similar within instrument (300) as was discussed inrelation to instrument (200) above. In particular, torque member (250)is configured to limit the amount of torque that may be applied tocouple a waveguide (320) with transducer assembly (100); and provideaudible/tactile feedback to indicate that the appropriate amount oftorque has been achieved. Instrument (300) of the present examplecomprises transducer assembly (100) and a shaft assembly (310). Shaftassembly (310) comprises a waveguide (320), sheath (230), a pair ofshroud halves (340, 342), a retaining ring (344), a retaining sleeve(346), torque member (250), connector (260), a retaining member (360),and a spring (370). Shaft assembly (310) also includes a user inputfeature (311) that is operable to selectively activate transducerassembly (100), to thereby selectively activate ultrasonic blade (324)of waveguide (320). User input feature (311) may be constructed andoperable in accordance with the teachings herein relating to user inputfeature (211) of instrument (200).

FIGS. 14A-14G show exemplary steps for assembling instrument (300). FIG.14A shows instrument (300) in a disassembled state, including shaftassembly (310) in a disassembled state. In an initial assembly step,waveguide (320) is inserted into interior bore (232) of sheath (230)such that an ultrasonic blade (324) of waveguide (320) extends from thedistal end of sheath (230) as shown in FIG. 14B. A transverse opening(328) of waveguide (320) is aligned with complementary transverseopenings (238) of sheath (230). Connector (260) is then coupled to aproximal surface of flange (234) of sheath (230), as shown in FIG. 14C.As described above, connector (260) is configured to insertingly fit incavity (108) of transducer assembly (100) and thereby guide shaftassembly (210) into aligned engagement with transducer assembly (100).As also described above, electrical contact features (262, 265) ofconnector (260) provide electrical coupling between user input feature(311) and transducer assembly (100).

As shown in FIG. 14D, torque member (250) is then positioned aboutsheath (230) such that the proximal surface of torque member (250) restsagainst the distal surface of flange (234). As noted above, sheath (230)fits into bore (252) of torque member (250), such that torque member(250) may simply be slid onto sheath (230). As also shown in FIG. 14D,spring (370) and retaining member (360) are also positioned about sheath(230). Spring (370) is positioned proximal to retaining member (360). Asbest seen in FIG. 16, retaining member (360) has a pair of openings(368) that align with openings (238, 328). A pin (326) is passed throughaligned openings (238, 328, 368) in sheath (230), waveguide (320), andretaining member (360) to thereby couple sheath (230), waveguide (320),and retaining member (360), such that rotation of sheath (230) causesconcurrent rotation of waveguide (320) and retaining member (360). Itshould therefore be understood that sheath (230), waveguide (320), andretaining member (360) rotate together unitarily when shaft assembly(310) is fully assembled. Opening (328) is located at a position alongthe length of waveguide (320) corresponding to a node associated withresonant ultrasonic vibrations communicated through waveguide (320),such that the ultrasonic vibrations are not communicated to pin (326).It should be understood that the steps shown in FIGS. 14C and 14D may bereversed, performed simultaneously, or otherwise be combined with otherassembly steps described herein.

Once connector (260) and torque member (250) have been suitablypositioned in relation to sheath (230), and sheath (230) and waveguide(320) have been coupled together with retaining member (360), shroudhalves (340, 342) are then maneuvered toward sheath (230) such that theproximal portion of sheath (230) is captured between shroud halves (340,342) as shown in FIG. 14E. As discussed above, an exterior surface oftorque member (250) presents a pair of longitudinal channels (258). Theinterior regions of shroud halves (340, 342) of the present example eachinclude a respective key feature (341, 343) configured to fit withinchannels (258) of torque member (250) when shroud halves (340, 342) arepositioned about torque member (250). Thus, as shroud halves (340, 342)are rotated, torque member (250) is concurrently rotated. It shouldtherefore be understood that shroud halves (340, 342) and torque member(250) rotate together unitarily when shaft assembly (310) is fullyassembled. The distal end of each shroud half (340, 342) includes arespective recess (390, 392). Recesses (390, 392) align with each otherto form a complete annular recess when shroud halves (340, 342) arejoined together as shown in FIG. 14E. Similarly, the proximal end ofeach shroud half (340, 342) includes a respective recess (394, 396).Recesses (394, 396) also align with each other to form a completeannular recess when shroud halves (340, 342) are joined together asshown in FIG. 14E.

Once shroud halves (340, 342) have been joined together as shown in FIG.14E, retaining ring (344) is slid proximally over aligned recesses (394,396), as shown in FIG. 14F. Similarly, retaining sleeve (346) is sliddistally over aligned recesses (390, 392), as also shown in FIG. 14F.Retaining ring (344) and sleeve (346) are configured to hold shroudhalves (340, 342) together. At this stage, shaft assembly (310) iscompletely assembled. Retaining ring (344) and sleeve (346) may engageshroud halves (340, 342) with an interference fit, such that retainingring (344) and sleeve (346) remain coupled with shroud halves (340, 342)due to friction. It should be understood that shaft assembly (310) maybe provided to an end user in the configuration shown in FIG. 14F, suchthat the end user need not perform any of the assembly steps shown inFIGS. 14A-14F.

Once shaft assembly (310) has been fully assembled, shaft assembly (310)may be readily coupled with transducer assembly (100) as shown in FIG.14G. In particular, the user may first maneuver shaft assembly (310)proximally toward transducer assembly (100). During this stage,connector (260) may assist in guiding shaft assembly (310) into axialalignment with transducer assembly (100) as noted above. The user maythen grasp shroud halves (340, 342) and rotate shaft assembly (310)relative to transducer assembly (100) to mechanically and acousticallycouple waveguide (320) with horn (120) via threaded stud (122) and athreaded bore (322) formed in a proximal end of waveguide (320).

As the user rotates rotate shaft assembly (310) relative to transducerassembly (100) to mechanically and acoustically couple waveguide (320)with horn (120), torque member (250) and sheath (230) may interact asdescribed above with respect to FIGS. 11A-11C. In particular, as theuser rotates shroud halves (240, 242) clockwise relative to transducerassembly (100) through a first range of motion, tabs (256) engagelongitudinal projections (236) such that torque member (250) rotatessheath (230) and waveguide (320) relative to transducer assembly (100).Waveguide (320) is thereby coupled with threaded stud (122) with acertain predetermined amount of torque. Once the assembly of waveguide(320) and threaded stud (122) reaches the predetermined amount oftorque, and the user continues to rotate shroud halves (240, 242)clockwise relative to transducer assembly (100) past the first range ofmotion, resilient members (254) deflect outwardly, such that torquemember (250) no longer rotates sheath (230). As the user continues torotate shroud halves (240, 242), tabs (256) snap inwardly and thusprovide audible and/or tactile feedback to indicate to the user that anappropriate amount of torque has been achieved in the coupling ofwaveguide (320) with threaded stud (122). Any further clockwise rotationof shroud halves (240, 242) and torque member (250) no longer causesrotation of sheath (230) and waveguide (320) relative to transducerassembly (100). If the user wishes to decouple shaft assembly (310) fromtransducer assembly (100), the user may grasp shroud halves (340, 342)with one hand and rotate shroud halves (340, 342) counterclockwiserelative to transducer assembly (100) while gripping transducer assembly(100) with the other hand, until waveguide (320) is decoupled fromthreaded stud (122) of transducer assembly (100). The user may thensimply pull shaft assembly (310) away from transducer assembly (100).

As shown in FIGS. 15 and 17A-17C, a proximal end of each shroud half(340, 342) includes an inwardly extending flange (362, 364). When shroudhalves (340, 342) are positioned about sheath (230), spring (370), andretaining member (360) are positioned distal to flanges (362, 364) suchthat spring (370) bears against a distal surface of flanges (362, 364)and a proximal surface of flange (362) of retaining member (360). Itshould therefore be understood spring (370) biases retaining member(360), sheath (230), and waveguide (320) distally relative to shroudhalves (340, 342). The proximal end of each shroud half (340, 342) alsoincludes an inwardly biased resilient tab (347, 348). Resilient tabs(347, 348) are configured to bear against an exterior surface of sleeveportion (106) of transducer assembly (100) when instrument (300) iscompletely assembled. FIGS. 17A-17C show the interaction of resilienttabs (347, 348) with sleeve portion (106) of transducer assembly (100)during the coupling of shaft assembly (310) with transducer assembly. Itshould be understood that the stages shown in FIGS. 17A-17C would beoccurring between the stage shown in FIG. 14F and the stage shown inFIG. 14G.

FIG. 17A shows shaft assembly (310) in an initial stage of engagementwith transducer assembly (100). In particular, threaded stud (122) ofhorn (120) has been partially threaded into threaded bore (322) ofwaveguide (320) in response to the user rotating shaft assembly (310)relative to transducer assembly (100). At this stage, sheath (230),connector (260), torque member (250), waveguide (320), and retainingmember (360) are all at a distal position relative to shroud halves(340, 342). As can also be seen in FIG. 17A, flange (261) is at a distalposition in relation to resilient tabs (347, 348) of shroud halves (340,342), such that resilient tabs (347, 348) are both at inwardly deflectedorientations. In the present example, the proximal edges of resilienttabs (347, 348) abut the distal annular edge of sleeve portion (106) oftransducer assembly (100) at this stage.

As the user continues to rotate shaft assembly (310) relative totransducer assembly (100), the engagement between threaded stud (122)and threaded bore (322) continues to draw the combination of sheath(230), connector (260), torque member (250), waveguide (320), andretaining member (360) proximally toward transducer assembly (100).However, shroud halves (340, 342) do not translate proximally, yet, dueto engagement between the proximal edges of resilient tabs (347, 348)abut the distal annular edge of sleeve portion (106). The combination ofsheath (230), connector (260), torque member (250), waveguide (320), andretaining member (360) thus translates proximally relative to shroudhalves (340, 342) in addition to translating proximally relative totransducer assembly (100) at this stage. While the combination of sheath(230), connector (260), torque member (250), waveguide (320), andretaining member (360) translates proximally relative to shroud halves(340, 342), retaining member (360) compresses spring (370) againstflanges (362, 364). As connector (260) translates proximally with thecombination of sheath (230), torque member (250), waveguide (320), andretaining member (360) relative to shroud halves (340, 342), flange(261) bears outwardly against resilient tabs (347, 348), such thatflange (261) eventually drives resilient tabs (347, 348) outwardly asshown in FIG. 17B. In particular, flange (261) drives resilient tabs(347, 348) outwardly to a point where resilient tabs (347, 348) areoriented substantially parallel to the longitudinal axis of instrument(300), such that resilient tabs (347, 348) are oriented to fit in a gapdefined between the outer diameter of sleeve portion (106) and the innerdiameter of retaining sleeve (346).

Once flange (261) has driven resilient tabs (347, 348) outwardly to apoint where resilient tabs (347, 348) are oriented to fit in the gapdefined between the outer diameter of sleeve portion (106) and the innerdiameter of retaining sleeve (346), the proximal resilient bias imposedby spring (370) drives shroud halves (340, 342) proximally towardtransducer assembly (100) as shown in FIG. 17C. At this stage, shroudhalves (340, 342) and the combination of sheath (230), connector (260),torque member (250), waveguide (320), and retaining member (360) are inproximal positions relative to transducer assembly. The user maycontinue to rotate shaft assembly (310) relative to transducer assembly(100) in order to achieve the appropriate amount of torque, as regulatedby torque member (250). In some versions, instrument (300) is configuredsuch that shroud halves (340, 342) snap back from the distal position ofFIG. 17B to the proximal position of FIG. 17C as soon as an appropriateamount of torque is achieved in the coupling of horn (120) withwaveguide (320). In some other versions, instrument (300) is configuredsuch that shroud halves (340, 342) snap back from the distal position ofFIG. 17B to the proximal position of FIG. 17C just before an appropriateamount of torque is achieved in the coupling of horn (120) withwaveguide (320). Thus, the snapping back of shroud halves (340, 342) mayfurther indicate to the user that the appropriate amount of torque hasbeen achieved or will soon be achieved.

C. Exemplary Integral Torque Assembly with Sliding Grip

FIGS. 18-22C show another exemplary instrument (400) having an integraltorque assembly (450). Instrument (400) of the present example isconfigured to operate substantially similar to instruments (10, 200,300) discussed above except for the differences discussed below.Instrument (400) is thus operable to transect and/or seal tissue at asurgical site. Furthermore, torque assembly (450) is configured tooperate substantially similar to the torque assemblies that includetorque members (250, 350) discussed above, except for the differencesdiscussed below. In particular, torque assembly (450) is configured tolimit the amount of torque that may be applied to couple a waveguide(420) with transducer assembly (100); and provide audible/tactilefeedback to indicate that the appropriate amount of torque has beenachieved.

Instrument (400) of the present example comprises transducer assembly(100) and a shaft assembly (410). Shaft assembly (410) comprises awaveguide (420), a sheath (430), a shroud (440), and a torque assembly(450). As shown in FIG. 19, sheath (430) defines a longitudinal interiorbore (432) that passes completely through sheath (430) from a proximalend to a distal end thus defining a proximal opening and a distalopening. Sheath (430) is configured to receive waveguide (420) withininterior bore (432). A pin (426) is passed through waveguide (420) andan elongate slot (438) formed in sheath (430) to thereby couple sheath(430) and waveguide (420) such that rotation of sheath (430) causesconcurrent rotation of waveguide (420). Pin (426) is located at aposition along the length of waveguide (420) corresponding to a nodeassociated with resonant ultrasonic vibrations communicated throughwaveguide (420). It should be understood that elongate slot (438) mayallow for some longitudinal translation of waveguide (420) and pin (426)relative to sheath (430). Shaft assembly (410) also includes a userinput feature (411) that is operable to selectively activate transducerassembly (100), to thereby selectively activate ultrasonic blade (424)of waveguide (420). User input feature (411) may be constructed andoperable in accordance with the teachings herein relating to user inputfeature (211) of instrument (200).

A proximal end of sheath (430) includes an annular flange (434) and aplurality of longitudinal projections (436) extending outwardly from anexterior surface of sheath (430). Torque assembly (450) comprises aratcheting pawl (452) and a ratcheting collar (460). Ractcheting pawl(452) defines a longitudinal interior bore (451) that passes completelythrough ractcheting pawl (452) from a proximal end to a distal end thusdefining a proximal opening and a distal opening. Interior bore (451) ofractcheting pawl (452) is configured to receive sheath (430) such that aproximal surface of ratcheting pawl (452) rests against a distal surfaceof flange (434). A plurality of longitudinal channels (453) are formedin the interior surface of interior bore (451) of ratcheting pawl (452).Longitudinal channels (453) are configured to receive longitudinalprojections (436) such that rotation of ratcheting pawl (452) causesconcurrent rotation of sheath (430). Ratcheting pawl (452) includes aplurality of resilient members (454) extending from an exterior surfaceof ratcheting pawl (452). Each resilient member (454) includes anoutwardly extending tab (456).

An exterior surface of ratcheting collar (460) presents a plurality ofinwardly directed and longitudinally extending recesses (462). Aninterior surface of shroud (440) presents a plurality of inwardlydirected and longitudinally extending projections (not shown). Shroud(440) is configured to receive ratcheting collar (460) such that theprojections of shroud (440) engage recesses (462). Thus, due to thisengagement, rotation of shroud (440) causes concurrent rotation ofcollar (460). An interior surface of collar (460) presents a pluralityof inwardly directed and longitudinally extending projections (464).Projections (464) are configured to engage tabs (456) of pawl (452) suchthat shroud (440) may be used to rotate and sheath (430) and waveguide(420) relative to transducer assembly (100). Resilient members (454) arefurther configured to provide slipping of tabs (456) relative toprojections (464) to thereby effectively limit the amount of torque thatmay be applied to waveguide (420) by shroud (440) and collar (460).

FIGS. 22A-22C show the interaction of pawl (452) and collar (460) aswaveguide (420) is connected with transducer assembly (100). As shroud(440) is rotated clockwise, ratcheting collar (460) rotates as wellbecause of the engagement between the longitudinal projections of shroud(440) and corresponding longitudinal channels (462) of collar (460). Ascollar (460) rotates clockwise, tabs (456) of ratcheting pawl (452)contact longitudinal projections (464) of ratcheting pawl (460) as shownin FIG. 22A. With tabs (456) engaging projections (464), the usercontinues to rotate shroud (440) and collar (460) clockwise relative totransducer assembly (100) through a first range of motion. During thisfirst range of motion, tabs (456) continue to engage projections (464)such that torque assembly (450) rotates sheath (430) and waveguide (420)relative to transducer assembly (100). Waveguide (420) is therebycoupled with threaded stud (122).

As the user completes the first range of motion, waveguide (420) issecured to threaded stud (122) with a certain predetermined amount oftorque. Once the assembly of waveguide (420) and threaded stud (122)reaches the predetermined amount of torque, and the user continues torotate shroud (440) and collar (460) clockwise relative to transducerassembly (100) past the first range of motion, resilient members (454)deflect inwardly as shown in FIG. 22B. In particular, projections (464)drive tabs (456) inwardly through a cam action, such that collar (460)no longer rotates pawl (452). Sheath (430) and waveguide (420) thusremain rotationally stationary at this stage. As the user continues torotate shroud (400), collar (460) continues to rotate such that tabs(456) eventually clear projections (464) and snap outwardly as shown inFIG. 22C. This outward snapping/ratcheting may provide audible and/ortactile feedback to indicate to the user that an appropriate amount oftorque has been achieved in the coupling of waveguide (420) withthreaded stud (122). It should be understood that from this point on,any further clockwise rotation of shroud (440) and collar (460) nolonger causes rotation of the combination of pawl (452), sheath (430),and waveguide (420) relative to transducer assembly (100). It shouldalso be understood that the rigidity of resilient members (454) may bechanged to thereby change the maximum amount of torque that may beapplied to waveguide (420).

As noted above, the integral torque assembly features of shaft assembly(410) eliminate the need for a separate torque wrench (e.g., such astorque wrench (50), etc.) to secure waveguide (420) with horn (120). Itshould also be understood that, during use of assembled instrument(400), the distal portion of sheath (430) proximal to ultrasonic blade(424) may be grasped by a user during operation to grasp instrument(400) in a pencil-like manner. Holding instrument (400) with a pencilgrip may enable the user to provide very fine and precise movement withblade (424), such as in a facial plastic surgery procedure or some otherfine and precise surgical procedure. In the present example, the distalportion of sheath (430) of comprises an ergonomic overmold (433) thatfurther facilitates a pencil grip. Other suitable features will beapparent to those of ordinary skill in the art in view of the teachingsherein.

In some versions of instrument (400), shroud (440) may translatelongitudinally relative to sheath (430). In some such versions, aresilient member may be used to resiliently bias shroud (440) relativeto sheath (430) (e.g., similar to spring (370), etc.). In addition or inthe alternative, sheath (430) may be resiliently biased relative totransducer assembly (100). It should also be understood that theproximal end of shroud (440) may be configured to threadably couple withsleeve portion (106) of transducer assembly (100). Furthermore, a foamfiller, spring, and/or other feature may be positioned between shroud(440) and sheath (430) to substantially maintain a spatial relationshipbetween shroud (440) and sheath (430) along transverse paths.

D. Exemplary Integral Torque Assembly with Bayonet Mount

FIGS. 23-27C show another exemplary instrument (500) having an integraltorque assembly (550). Instrument (500) of the present example isconfigured to operate substantially similar to instruments (10, 200,300, 400) discussed above except for the differences discussed below.Instrument (500) is thus operable to transect and/or seal tissue at asurgical site. Furthermore, torque assembly (550) is configured tooperate substantially similar to the torque assemblies that includedtorque members (250, 350) and torque assembly (450) discussed above,except for the differences discussed below. In particular, torqueassembly (550) is configured to limit the amount of torque that may beapplied to couple a waveguide (520) with transducer assembly (100); andprovide audible/tactile feedback to indicate that the appropriate amountof torque has been achieved.

Instrument (500) of the present example comprises transducer assembly(100) and a shaft assembly (510). Shaft assembly (510) comprises awaveguide (520), a sheath (530), a shroud (540), and a locking cylinder(542). Shaft assembly (510) also includes a user input feature (511)that is operable to selectively activate transducer assembly (100), tothereby selectively activate ultrasonic blade (524) of waveguide (520).User input feature (511) may be constructed and operable in accordancewith the teachings herein relating to user input feature (211) ofinstrument (200). A distal end of locking cylinder (542) is rotatablycoupled with a proximal end of shroud (540) such that shroud (540) isrotatable relative to locking cylinder (542). Locking cylinder (542)comprises a longitudinal channel (541) formed in an interior surface oflocking cylinder (542). Longitudinal channel (541) extendslongitudinally distally from a proximal end of locking cylinder (542) toa lateral opening (543) formed through locking cylinder (542). Sleeveportion (106) of transducer assembly (100) of the present examplecomprises a pin (107) extending outwardly from the exterior surface ofsleeve portion (106).

Longitudinal channel (541) is configured to receive pin (107) astransducer assembly (100) is passed longitudinally into locking cylinder(542) as shown in FIGS. 24A-24C. Once pin (107) reaches lateral opening(543), locking cylinder (542) is rotated clockwise relative totransducer assembly (100) such that pin (107) becomes positioned withinlateral opening (546), which extends laterally in relation to channel(541), as shown in FIG. 24C. It should therefore be understood thatlocking cylinder (542) is coupled with transducer assembly (100) in abayonet-like manner. This coupling prevents shaft assembly (510) fromsliding distally off of transducer assembly (100), though sheath (530),waveguide (520), and shroud (540) are still rotatable relative totransducer assembly (100) at this stage. It should further be understoodthat any further rotation of shroud (540) relative to transducerassembly (100) will not be communicated to locking member (542) becauseof contact between pin (107) and an interior surface of lateral opening(543).

As shown in FIG. 25, sheath (530) defines a longitudinal interior bore(532) that passes completely through sheath (530) from a proximal end toa distal end thus defining a proximal opening and a distal opening.Sheath (530) is configured to receive waveguide (520) within interiorbore (532). A pin (526) is passed through waveguide (520) and sheath(530) to thereby couple sheath (530) and waveguide (520) such thatrotation of sheath (530) causes concurrent rotation of waveguide (520).Pin (526) is located at a position along the length of waveguide (520)corresponding to a node associated with resonant ultrasonic vibrationscommunicated through waveguide (520).

As best seen in FIG. 26, a proximal end of sheath (530) includes atorque assembly (550). Torque assembly (550) comprises a pair ofsemi-circular resilient members (552) coupled to an exterior surface ofsheath (530) via a respective pair of radially extending projections(554). Each resilient member (552) includes an outwardly extending tab(556). Shroud (540) comprises a plurality of inwardly extendinglongitudinal projections (542) disposed in an angular array about aninterior surface of shroud (540). Longitudinal projections (542) areconfigured to engage tabs (556) of resilient members (552) such thatshroud (540) may be used to rotate and sheath (530) and waveguide (520)relative to transducer assembly (100). Resilient members (552) arefurther configured to provide slipping of tabs (556) relative toprojections (542) to thereby effectively limit the amount of torque thatmay be applied to waveguide (520) by shroud (540).

FIGS. 27A-27C show the interaction of resilient members (552) and shroud(540) as waveguide (520) is connected with transducer assembly (100). Asshroud (540) is rotated clockwise, tabs (556) of resilient members (552)contact longitudinal projections (544) of shroud (540) as shown in FIG.27A. Thus, as shroud (540) is rotated clockwise relative to transducerassembly (100), projections (544) and tabs (556) cooperate to drivesheath (530) clockwise, thereby rotating waveguide (520) clockwiserelative to transducer assembly (100) through a first range of motion.During this first range of motion, tabs (556) continue to engageprojections (544) such that torque assembly (550) rotates sheath (530)and waveguide (520) relative to transducer assembly (100). Waveguide(520) is thereby coupled with threaded stud (122).

As the user completes the first range of motion, waveguide (520) issecured to threaded stud (122) with a certain predetermined amount oftorque. Once the assembly of waveguide (520) and threaded stud (122)reaches the predetermined amount of torque, and the user continues torotate shroud (540) clockwise relative to transducer assembly (100) pastthe first range of motion, resilient members (552) deflect inwardly asshown in FIG. 27B. In particular, projections (544) drive tabs (556)inwardly through a cam action, such that shroud (540) no longer rotatessheath (530). Sheath (530) and waveguide (520) thus remain rotationallystationary at this stage. As the user continues to rotate shroud (540),tabs (556) eventually clear projections (544) and snap outwardly asshown in FIG. 27C. This outward snapping/ratcheting may provide audibleand/or tactile feedback to indicate to the user that an appropriateamount of torque has been achieved in the coupling of waveguide (520)with threaded stud (122). It should be understood that from this pointon, any further clockwise rotation of shroud (540) no longer causesrotation of sheath (530) and waveguide (530) relative to transducerassembly (100). It should also be understood that the rigidity ofresilient members (552) may be changed to thereby change the maximumamount of torque that may be applied to waveguide (520).

A surface (556B) of each tab (556) is substantially flat such that asshroud (540) is rotated counterclockwise relative to transducer assembly(100), contact between longitudinal projections (544) and tabs (556)will not drive resilient members (552) inwardly. It should therefore beunderstood that rotation of shroud (540) relative to transducer assembly(100) in a counterclockwise motion will not cause slipping or ratchetingof torque assembly (550). Thus, when the user wishes to disassembleshaft assembly (510) from transducer assembly (100) at the end of asurgical procedure, the user may simply grasp shroud (540) with one handand rotate shroud (540) counterclockwise relative to transducer assembly(100) while gripping transducer assembly (100) with the other hand,until waveguide (520) is decoupled from threaded stud (122) oftransducer assembly (100). The user may then rotate locking cylinder(542) relative to transducer assembly to disengage pin (107) fromlateral opening (546), then simply pull shaft assembly (510) away fromtransducer assembly (100). At this stage, shaft assembly (510) may bedisposed of; while transducer assembly (100) may be reconditioned anyre-used. Alternatively, the user may wish to handle these components insome other fashion.

As noted above, the integral torque assembly features of shaft assembly(510) eliminate the need for a separate torque wrench (e.g., such astorque wrench (50), etc.) to secure waveguide (520) with horn (120). Itshould also be understood that, during use of assembled instrument(500), the distal portion of sheath (530) proximal to ultrasonic blade(524) may be grasped by a user during operation to grasp instrument(500) in a pencil-like manner. Holding instrument (500) with a pencilgrip may enable the user to provide very fine and precise movement withblade (524), such as in a facial plastic surgery procedure or some otherfine and precise surgical procedure. In the present example, the distalportion of sheath (530) of comprises an ergonomic overmold (533) thatfurther facilitates a pencil grip. Other suitable features will beapparent to those of ordinary skill in the art in view of the teachingsherein.

E. Exemplary Integral Torque Assembly with Slip Ring

FIGS. 28-31 show another exemplary instrument (600) having an integraltorque assembly (650). Instrument (600) of the present example isconfigured to operate substantially similar to instruments (10, 200,300, 400, 500) discussed above except for the differences discussedbelow. Instrument (600) is thus operable to transect and/or seal thetissue at a surgical site. Furthermore, torque assembly (650) isconfigured to operate substantially similar to the torque assembliesthat included torque members (250, 350), and torque assemblies (450,550) discussed above except for the differences discussed below. Inparticular, torque assembly (650) is configured to limit the amount oftorque that may be applied to couple a waveguide (620) with transducerassembly (100); and provide audible/tactile feedback to indicate thatthe appropriate amount of torque has been achieved.

Instrument (600) of the present example comprises transducer assembly(100) and a shaft assembly (610). Shaft assembly (610) comprises awaveguide (620), a sheath (630), a shroud (640), and an outer cuff(642). Shaft assembly (610) also includes a user input feature (611)that is operable to selectively activate transducer assembly (100), tothereby selectively activate ultrasonic blade (624) of waveguide (620).User input feature (611) may be constructed and operable in accordancewith the teachings herein relating to user input feature (211) ofinstrument (200). A distal end of outer cuff (642) comprises a pluralityof rectangular projections (643). A proximal end of shroud (640)presents a plurality of longitudinal channels (641) configured toreceive rectangular projections (643) such that outer cuff (642) andshroud (640) rotate together. The interior of outer cuff (642) includesa threading (not shown) that is configured to complement an exteriorthreading on sleeve portion (106) of transducer assembly (100). Outercuff (642) may thus be threadably coupled with sleeve portion (106). Inthe present example, as an initial stage of securing shaft assembly(610) to transducer assembly (100), the user first begins threadingouter cuff (642) onto sleeve portion (106). This will provide alignmentand seating of waveguide (620) with threaded stud (122) of horn (120).

Sheath (630) defines a longitudinal interior bore (632) that passescompletely through sheath (630) from a proximal end to a distal end thusdefining a proximal opening and a distal opening. Sheath (630) isconfigured to receive waveguide (620) within interior bore (632). Asbest seen in FIG. 30, a pin (626) is passed through waveguide (620) andsheath (630) to thereby couple sheath (630) and waveguide (620) suchthat rotation of sheath (630) causes concurrent rotation of waveguide(620). Pin (626) is located at a position along the length of waveguide(620) corresponding to a node associated with resonant ultrasonicvibrations communicated through waveguide (620).

As best seen in FIGS. 28 and 31, a proximal end of sheath (630) includesa torque assembly (650). Torque assembly (650) is configured to operatesubstantially similar to torque assembly (550) discussed above. Forinstance, torque assembly (650) comprises a pair of semi-circularresilient members (652) coupled to an exterior surface of sheath (630)via a corresponding pair of projections (654). Each resilient member(652) includes an outwardly extending tab (656). Shroud (640) comprisesa plurality of inwardly extending longitudinal projections (642)disposed in an angular array about an interior surface of shroud (640).Longitudinal projections (642) are configured to engage tabs (656) ofresilient members (652) such that shroud (640) may be used to rotate andsheath (630) and waveguide (620) relative to transducer assembly (100).Resilient members (652) are further configured to provide slipping oftabs (656) relative to projections (642) to thereby effectively limitthe amount of torque that may be applied to waveguide (620) by shroud(640).

It should be understood from the foregoing that, as the user rotatesrotate shaft assembly (610) relative to transducer assembly (100) tomechanically and acoustically couple waveguide (620) with horn (120),torque assembly (650) may operate as described above with respect toFIGS. 27A-27C. In particular, as the user rotates shroud (640) clockwiserelative to transducer assembly (100) through a first range of motion,projections (644) and tabs (656) cooperate to drive sheath (630)clockwise, thereby rotating waveguide (620) clockwise relative totransducer assembly (100) through a first range of motion. During thisfirst range of motion, tabs (656) continue to engage projections (644)such that torque assembly (650) rotates sheath (630) and waveguide (620)relative to transducer assembly (100). Waveguide (620) is therebycoupled with threaded stud (122).

As the user completes the first range of motion, waveguide (620) issecured to threaded stud (122) with a certain predetermined amount oftorque. Once the assembly of waveguide (620) and threaded stud (122)reaches the predetermined amount of torque, and the user continues torotate shroud (640) clockwise relative to transducer assembly (100) pastthe first range of motion, resilient members (652) deflect inwardly,such that shroud (640) no longer rotates sheath (630). Sheath (630) andwaveguide (620) thus remain rotationally stationary at this stage. Asthe user continues to rotate shroud (640), tabs (656) eventually clearprojections (644) and snap outwardly, thereby providing audible and/ortactile feedback to indicate to the user that an appropriate amount oftorque has been achieved in the coupling of waveguide (620) withthreaded stud (122). It should be understood that from this point on,any further clockwise rotation of shroud (640) no longer causes rotationof sheath (630) and waveguide (630) relative to transducer assembly(100). To remove shaft assembly (610) from transducer assembly (100),the user may simply grasp shroud (640) and rotate shaft assembly (610)counterclockwise relative to transducer assembly (100). At this stage,shaft assembly (610) may be disposed of; while transducer assembly (100)may be reconditioned any re-used. Alternatively, the user may wish tohandle these components in some other fashion.

As noted above, the integral torque assembly features of shaft assembly(610) eliminate the need for a separate torque wrench (e.g., such astorque wrench (50), etc.) to secure waveguide (620) with horn (120). Itshould also be understood that, during use of assembled instrument(600), the distal portion of sheath (630) proximal to ultrasonic blade(624) may be grasped by a user during operation to grasp instrument(600) in a pencil-like manner. Holding instrument (600) with a pencilgrip may enable the user to provide very fine and precise movement withblade (624), such as in a facial plastic surgery procedure or some otherfine and precise surgical procedure. In the present example, the distalportion of sheath (630) comprises an ergonomic overmold (633) that isconfigured to facilitate gripping of instrument (600) using a pencilgrip. As shown in FIG. 29, overmold (633) comprises a first piece (633A)and a second piece (633B) such that overmold (633) may be selectivelycoupled to a distal end of shroud (640) and/or be otherwise securedrelative to waveguide (620). Other suitable features will be apparent tothose of ordinary skill in the art in view of the teachings herein.

F. Exemplary Integral Torque Assembly with Slide-On Shroud

FIGS. 32-36 show another exemplary instrument (700) having an integraltorque assembly. Instrument (700) of the present example is configuredto operate substantially similar to instruments (10, 200, 300, 400, 500,600) discussed above except for the differences discussed below. Inparticular, instrument (700) is operable to transect and/or seal thetissue at a surgical site. Furthermore, the torque assembly discussedbelow is configured to operate substantially similar to the torqueassemblies that included torque members (250, 350), and torqueassemblies (450, 550, 650) discussed above except for the differencesdiscussed below. In particular, the torque assembly discussed below isconfigured to limit the amount of torque that may be applied to couple awaveguide (720) with transducer assembly (100); and provideaudible/tactile feedback to indicate that the appropriate amount oftorque has been achieved.

Instrument (700) of the present example comprises transducer assembly(100) and a shaft assembly (710). Shaft assembly (710) comprises awaveguide (720), a sheath (730), a shroud (740), and a connector (760).Shaft assembly (610) also includes a user input feature (711) that isoperable to selectively activate transducer assembly (100), to therebyselectively activate ultrasonic blade (724) of waveguide (720). Userinput feature (711) may be constructed and operable in accordance withthe teachings herein relating to user input feature (211) of instrument(200). As best seen in FIG. 34, shroud (740) includes an angular arrayof proximally projecting arms (742). An inwardly extending latchingfeature (743) is positioned at the free end of each arm (742). Arms(742) are resiliently biased to assume the straight configurations shownin FIG. 34. As also shown in FIG. 34, shroud (740) also includes anangular array of inwardly projecting projections (744) that extendlongitudinally along part of the length of the interior of shroud (740).

Sheath (730) defines a longitudinal interior bore (732) that passescompletely through sheath (730) from a proximal end to a distal end thusdefining a proximal opening and a distal opening. As best seen in FIG.35, the proximal end of sheath (730) further includes a pair ofproximally projecting arms (734). An outwardly extending latchingfeature (735) is positioned at the free end of each arm (734). Arms(734) are resiliently biased to assume the straight configurations shownin FIG. 35. As also shown in FIG. 35, sheath (730) further includes apair of diametrically opposed resilient features (736). Resilientfeatures (736) each include a respective outwardly oriented tab (737).In addition, sheath (730) includes an annular recess (738) that isformed distal to resilient features (736).

FIGS. 33A-33E show exemplary assembly steps of instrument (700). FIG.33A shows instrument (700) in a disassembled state, including shaftassembly (710) in a disassembled state. In an initial assembly step,waveguide (720) is inserted into interior bore (732) of sheath (730)such that ultrasonic blade (724) of waveguide (720) extends from thedistal end of sheath (730) as shown in FIG. 33B. A pin (726) is passedthrough aligned openings in sheath (730) and waveguide (720) to therebycouple sheath (730) and waveguide (720), such that rotation of sheath(730) causes concurrent rotation of waveguide (720). It should thereforebe understood that sheath (730) and waveguide (720) rotate togetherunitarily when shaft assembly (710) is fully assembled. Pin (726) isinserted at a position along the length of waveguide (720) correspondingto a node associated with resonant ultrasonic vibrations communicatedthrough waveguide (720), such that the ultrasonic vibrations are notcommunicated to pin (726).

With sheath (730) and waveguide (720) coupled together, connector (260)is then coupled to arms (734) of sheath (730) as shown in FIGS. 33C and36. In particular, latching features (735) cam against openings (notshown) formed in connector (260), initially deflecting arms (734)inwardly as arms (734) are pressed into connector (260). Once latchingfeatures (734) clear the openings, the resilient bias drives arms (734)back outwardly to straight positions, such that latching features (734)engage corresponding proximal surfaces of connector (260). Connector(260) is thus secured to sheath (730) through a snap fit. As describedabove, connector (260) is configured to insertingly fit in cavity (108)of transducer assembly (100) and thereby guide shaft assembly (710) intoaligned engagement with transducer assembly (100). As also describedabove, electrical contact features (262, 265) of connector (260) provideelectrical coupling between user input feature (711) and transducerassembly (100).

With connector (260) secured to sheath (730), shroud (740) is then slidproximally over sheath (730) as shown in FIG. 33D. During this movement,arms (742) of shroud (742) deflect outwardly until shroud (742) reachesa proximal position where latching features (743) are aligned withannular recess (738) of sheath (730). Upon reaching this position, theresilient bias of arms (742) drives latching features (743) inwardlyinto engagement with annular recess (738) as shown in FIG. 36. Shroud(740) is thus secured to sheath (730) through a snap fit. At this stage,shaft assembly (710) is completely assembled. It should be understoodthat shaft assembly (710) may be provided to an end user in theconfiguration shown in FIG. 33D, such that the end user need not performany of the assembly steps shown in FIGS. 33A-33D.

Once shaft assembly (710) has been fully assembled, shaft assembly (710)may be readily coupled with transducer assembly (100) as shown in FIG.33E. In particular, the user may first maneuver shaft assembly (710)proximally toward transducer assembly (100). During this stage,connector (260) may assist in guiding shaft assembly (710) into axialalignment with transducer assembly (100) as noted above. The user maythen grasp shroud (740) and rotate shaft assembly (710) relative totransducer assembly (100) to mechanically and acoustically couplewaveguide (720) with horn (120) via threaded stud (122) and a threadedbore (722) formed in a proximal end of waveguide (720). As the userrotates rotate shaft assembly (710) relative to transducer assembly(100) to mechanically and acoustically couple waveguide (720) with horn(120), projections (744) may engage tabs (737). With projections (744)engaging tabs (737), the user continues to rotate shroud (740) clockwiserelative to transducer assembly (100) through a first range of motion.During this first range of motion, shroud (740) rotates sheath (730) andwaveguide (720) relative to transducer assembly (100). Waveguide (720)is thereby coupled with threaded stud (122).

As the user completes the first range of motion, waveguide (720) issecured to threaded stud (122) with a certain predetermined amount oftorque. Once the assembly of waveguide (720) and threaded stud (122)reaches the predetermined amount of torque, and the user continues torotate shroud (740) clockwise relative to transducer assembly (100) pastthe first range of motion, resilient features (736) deflect inwardly,such that shroud (740) no longer rotates sheath (730). As the usercontinues to rotate shroud (740), projections (744) eventually cleartabs (737) such that tabs snap outwardly. This outwardsnapping/ratcheting may provide audible and/or tactile feedback toindicate to the user that an appropriate amount of torque has beenachieved in the coupling of waveguide (720) with threaded stud (122). Itshould be understood that from this point on, any further clockwiserotation of shroud (740) no longer causes rotation of sheath (730) andwaveguide (720) relative to transducer assembly (100). It should also beunderstood that the rigidity of resilient features (736) may be changedto thereby change the maximum amount of torque that may be applied towaveguide (720).

Tabs (737) of the present example are configured such that rotation ofshroud (740) relative to transducer assembly (100) in a counterclockwisemotion will not cause slipping or ratcheting of resilient features(736). Thus, when the user wishes to disassemble shaft assembly (710)from transducer assembly (100) at the end of a surgical procedure, theuser may simply grasp shroud (740) with one hand and rotate shroud (740)counterclockwise relative to transducer assembly (100) while grippingtransducer assembly (100) with the other hand, until waveguide (720) isdecoupled from threaded stud (122) of transducer assembly (100). Theuser may then simply pull shaft assembly (710) away from transducerassembly (100). At this stage, shaft assembly (710) may be disposed of;while transducer assembly (100) may be reconditioned any re-used.Alternatively, the user may wish to handle these components in someother fashion.

It should be understood that the integral torque assembly features ofshaft assembly (710) eliminate the need for a separate torque wrench(e.g., such as torque wrench (50), etc.) to secure waveguide (720) withhorn (120). It should also be understood that, during use of assembledinstrument (700), the distal portion of sheath (730) proximal toultrasonic blade (724) may be grasped by a user during operation tograsp instrument (700) in a pencil-like manner. Holding instrument (700)with a pencil grip may enable the user to provide very fine and precisemovement with blade (724), such as in a facial plastic surgery procedureor some other fine and precise surgical procedure.

III. Miscellaneous

It should be understood that any of the versions of instrumentsdescribed herein may include various other features in addition to or inlieu of those described above. By way of example only, any of theinstruments described herein may also include one or more of the variousfeatures disclosed in any of the various references that areincorporated by reference herein. It should also be understood that theteachings herein may be readily applied to any of the instrumentsdescribed in any of the other references cited herein, such that theteachings herein may be readily combined with the teachings of any ofthe references cited herein in numerous ways. Other types of instrumentsinto which the teachings herein may be incorporated will be apparent tothose of ordinary skill in the art.

It should be appreciated that any patent, publication, or otherdisclosure material, in whole or in part, that is said to beincorporated by reference herein is incorporated herein only to theextent that the incorporated material does not conflict with existingdefinitions, statements, or other disclosure material set forth in thisdisclosure. As such, and to the extent necessary, the disclosure asexplicitly set forth herein supersedes any conflicting materialincorporated herein by reference. Any material, or portion thereof, thatis said to be incorporated by reference herein, but which conflicts withexisting definitions, statements, or other disclosure material set forthherein will only be incorporated to the extent that no conflict arisesbetween that incorporated material and the existing disclosure material.

Versions of the devices described above may have application inconventional medical treatments and procedures conducted by a medicalprofessional, as well as application in robotic-assisted medicaltreatments and procedures. By way of example only, various teachingsherein may be readily incorporated into a robotic surgical system suchas the DAVINCI™ system by Intuitive Surgical, Inc., of Sunnyvale, Calif.Similarly, those of ordinary skill in the art will recognize thatvarious teachings herein may be readily combined with various teachingsof U.S. Pat. No. 6,783,524, entitled “Robotic Surgical Tool withUltrasound Cauterizing and Cutting Instrument,” published Aug. 31, 5004,the disclosure of which is incorporated by reference herein.

Versions described above may be designed to be disposed of after asingle use, or they can be designed to be used multiple times. Versionsmay, in either or both cases, be reconditioned for reuse after at leastone use. Reconditioning may include any combination of the steps ofdisassembly of the device, followed by cleaning or replacement ofparticular pieces, and subsequent reassembly. In particular, someversions of the device may be disassembled, and any number of theparticular pieces or parts of the device may be selectively replaced orremoved in any combination. Upon cleaning and/or replacement ofparticular parts, some versions of the device may be reassembled forsubsequent use either at a reconditioning facility, or by a userimmediately prior to a procedure. Those skilled in the art willappreciate that reconditioning of a device may utilize a variety oftechniques for disassembly, cleaning/replacement, and reassembly. Use ofsuch techniques, and the resulting reconditioned device, are all withinthe scope of the present application.

By way of example only, versions described herein may be sterilizedbefore and/or after a procedure. In one sterilization technique, thedevice is placed in a closed and sealed container, such as a plastic orTYVEK bag. The container and device may then be placed in a field ofradiation that can penetrate the container, such as gamma radiation,x-rays, or high-energy electrons. The radiation may kill bacteria on thedevice and in the container. The sterilized device may then be stored inthe sterile container for later use. A device may also be sterilizedusing any other technique known in the art, including but not limited tobeta or gamma radiation, ethylene oxide, or steam.

Having shown and described various embodiments of the present invention,further adaptations of the methods and systems described herein may beaccomplished by appropriate modifications by one of ordinary skill inthe art without departing from the scope of the present invention.Several of such potential modifications have been mentioned, and otherswill be apparent to those skilled in the art. For instance, theexamples, embodiments, geometrics, materials, dimensions, ratios, steps,and the like discussed above are illustrative and are not required.Accordingly, the scope of the present invention should be considered interms of the following claims and is understood not to be limited to thedetails of structure and operation shown and described in thespecification and drawings.

We claim:
 1. A surgical instrument comprising: (a) a transducerassembly, wherein the transducer assembly is operable to convertelectrical power into ultrasonic vibrations; and (b) a shaft assembly,wherein the shaft assembly comprises: (i) an ultrasonic waveguide,wherein the ultrasonic waveguide is configured to couple with thetransducer assembly, (ii) a sheath, wherein the ultrasonic waveguide isdisposed within the sheath, (iii) a shroud defining an interior bore,wherein the sheath extends through the shroud, wherein the sheathextends distally past the shroud, and (iv) a torque transfer assembly atleast partially contained within the interior bore of the shroud,wherein the torque transfer assembly is configured to transfer apredetermined range of torque from the shroud to the ultrasonicwaveguide to thereby couple the ultrasonic waveguide with the transducerassembly, and wherein the torque transfer assembly is further configuredto rotate relative to the sheath and the ultrasonic waveguide to preventtransfer of torque from the shroud to the ultrasonic waveguide beyond anupper limit of the predetermined range.
 2. The surgical instrument ofclaim 1, wherein the torque transfer assembly comprises a resilientmember resiliently biased toward a first position, and wherein theresilient member is configured to transfer torque from the shroud to theultrasonic waveguide when the resilient member is in the first position.3. The surgical instrument of claim 2, wherein the sheath is operable todrive the resilient member to a second position in response to thetorque exceeding the upper limit of the predetermined range.
 4. Thesurgical instrument of claim 3, wherein the resilient member is unableto transfer torque from the shroud to the ultrasonic waveguide when theresilient member is in the second position.
 5. The surgical instrumentof claim 1, wherein the sheath is secured to the ultrasonic waveguide,and wherein the torque transfer assembly is configured to transfer thepredetermined range of torque from the shroud to the ultrasonicwaveguide via the sheath.
 6. The surgical instrument of claim 5, whereinthe sheath comprises a plurality of longitudinal projections configuredto receive the predetermined range of torque from the shroud of theultrasonic waveguide.
 7. The surgical instrument of claim 6, wherein theplurality of longitudinal projections are arranged in a circumferentialarray.
 8. The surgical instrument of claim 6, wherein each of theplurality of longitudinal projections comprises an angular surface and asubstantially flat surface.
 9. The surgical instrument of claim 1,wherein the torque transfer assembly defines a longitudinal channel, andwherein the shroud is configured to engage the longitudinal channel totransfer torque from the shroud to the torque transfer assembly.
 10. Thesurgical instrument of claim 1, further comprising a retaining ring,wherein the shroud includes a first body and a second body, and whereinthe retaining ring is configured to couple the first body and the secondbody such that the shroud at least partially contains the torquetransfer assembly.
 11. The surgical instrument of claim 10, wherein thefirst body and the second body collectively define a recess dimensionedto receive the retaining ring.
 12. The surgical instrument of claim 11,wherein the retaining ring is configured to couple with the first bodyand the second body via a friction fitting.
 13. The surgical instrumentof claim 1, wherein the torque transfer assembly comprises a resilienttab configured to prevent transfer of torque from the shroud to theultrasonic waveguide beyond the upper limit of the predetermined rangein a first rotational direction.
 14. The surgical instrument of claim13, wherein the resilient tab is configured to allow transfer of torquefrom the shroud to the ultrasonic waveguide beyond the upper limit ofthe predetermined range in a second rotational direction.
 15. Thesurgical instrument of claim 14, wherein the resilient tab comprises anangled surface and a substantially flat surface.
 16. The surgicalinstrument of claim 15, wherein the substantially flat surface isconfigured to engage the sheath in the second rotational direction. 17.The surgical instrument of claim 16, wherein the angled surface isconfigured to engage the sheath in the first rotational direction.
 18. Asurgical instrument, comprising: (a) a transducer assembly, wherein thetransducer assembly is operable to convert electrical power intoultrasonic vibrations; and (b) a shaft assembly, wherein the shaftassembly comprises: (i) an ultrasonic waveguide, wherein the ultrasonicwaveguide is configured to couple with the transducer assembly, (ii) asheath, wherein the ultrasonic waveguide is disposed within the sheath,(iii) a shroud, wherein at least part of the ultrasonic waveguideextends distally from the shroud, wherein the sheath extends distallypast the shroud, and (iv) a torque transfer assembly at least partiallycontained within the shroud and disposed on the ultrasonic waveguidesuch that the torque transfer assembly is radially interposed betweenthe shroud and the ultrasonic waveguide, wherein the torque transferassembly is configured to transfer torque from the shroud to theultrasonic waveguide to thereby couple the ultrasonic waveguide with thetransducer assembly as the shroud is rotated through a first range ofmotion, wherein the torque transfer assembly is configured to unitarilyrotate with the shroud to prevent the transfer of torque from the shroudto the ultrasonic waveguide as the shroud is rotated through a secondrange of motion.
 19. The surgical instrument of claim 18, wherein thetorque transfer assembly is configured such that a transition from thefirst range of motion to the second range of motion is associated with apredetermined torque threshold.
 20. A surgical instrument, comprising:(a) a transducer assembly, wherein the transducer assembly is operableto convert electrical power into ultrasonic vibrations; and (b) a shaftassembly, wherein the shaft assembly comprises: (i) an ultrasonicwaveguide, wherein the ultrasonic waveguide is configured to couple withthe transducer assembly, (ii) a shroud defining an interior bore,wherein at least a portion of the ultrasonic waveguide is housed withinthe shroud, and (iii) a torque transfer assembly housed within theinterior bore of the shroud, wherein the torque transfer assembly isconfigured to transfer a predetermined range of torque from the shroudto the ultrasonic waveguide to thereby couple the ultrasonic waveguidewith the transducer assembly, wherein the torque transfer assembly isfurther configured to unitarily rotate with the shroud relative to theultrasonic waveguide to prevent transfer of torque from the shroud tothe ultrasonic waveguide beyond an upper limit of the predeterminedrange, wherein the torque transfer assembly defines a longitudinalchannel, and wherein the shroud is configured to engage the longitudinalchannel to transfer torque from the shroud to the torque transferassembly.